1. Field of Invention
The present invention relates generally to an apparatus and method for forming a retainer or retainers in a suture and, more particularly, to an apparatus including a rotary retainer forming member for forming a retainer or retainers in a suture and method thereof.
2. Discussion of Related Art
A suture is an elongated body such as, for example, a strand, filament, wire, or thread, that typically includes a needle attached or formed on at least one end. In general, sutures are used in surgical procedures to close surgical and traumatic wounds, to close the skin in plastic surgery, to secure damaged or severed tendons, muscles or other internal tissues, and in microsurgery on nerves and blood vessels. Closure of wounds and/or holding tissues together facilitates healing and re-growth.
Complications associated with knots when using conventional sutures are well known. Such complications may include, for example: suture breakage, knot slippage, suture extrusion, infection, dehiscence and excessive inflammatory response leading to ischemia and scarring. Attempts to overcome these deficiencies with knotless sutures in the past have gained little clinical success. More recently, the development of self-retaining sutures such as, for example, barbed sutures, has been reported.
A self-retaining suture may be a one-way needle-drawn knotless suture which allows passage of the suture in one direction through tissue, but not in the opposite direction. A self-retaining suture may generally include a pointed leading end such as, for example, a needle, and a plurality of axially and circumferentially spaced retainers on the exterior surface of the suture. The retainers may generally be formed to collectively extend in one direction along a length of the suture. While suturing tissue, these retainers may penetrate inside the tissue and lock in place so that no knots are needed to tie the suture.
Methods of using self-retaining sutures in surgical procedures are disclosed, for example, in U.S. Pat. No. 6,599,310, entitled “Suture Method”, the disclosure of which is incorporated herein by reference. Self-retaining sutures provide the ability to put tension in the tissue with the result of less slippage of the suture in the wound. Depending on the circumstances of a given tissue repair, a given configuration of retainers on the exterior of the suture may be more preferable than another.
Various methods and apparatuses for forming retainers on the exterior of a suture have been proposed. For example, U.S. Pat. Nos. 7,225,512, 6,848,152, and 5,931,855, each of which is hereby incorporated herein by reference in its entirety, are related to self-retaining sutures and methods for making such sutures. In general, however, these apparatuses and methods may be directed to linearly reciprocating cutting devices and the like which require the suture to be twisted or rotated about its axis in order for retainers to be formed about the periphery thereof.